The prognostic value of a positive ctDNA test in urothelial cancer intensifies throughout the treatment journey. Failure to clear ctDNA after neoadjuvant therapy and then surgery is associated with a dramatically increasing hazard ratio for death, signaling profound treatment failure.

Following high response rates to systemic therapies like EV Pembro, using radiation for bladder preservation is now questioned. It may constitute overtreatment by radiating a now cancer-free organ, while providing no benefit for the systemic micrometastases that are the primary driver of mortality.

Achieving a pathologic complete response (path CR) in the bladder after neoadjuvant therapy is a marker of drug efficacy, not a signal to stop treatment. Because patients die from metastatic, not local, disease, a path CR should be seen as a reason to "double down" on the effective systemic therapy to eradicate micrometastases.

For bladder cancer patients with micrometastatic disease, the standard cystectomy requires a significant delay for the operation and recovery. This window may allow unseen metastases to progress, suggesting that upfront, effective systemic therapy is more critical for survival than immediate major surgery.

Professor Powles highlights a critical limitation of ctDNA in bladder cancer management. While excellent for assessing systemic risk, ctDNA may remain negative during a local, non-muscle invasive relapse (e.g., T1 cancer). This necessitates continued local surveillance like cystoscopy, even in ctDNA-negative patients pursuing bladder-sparing approaches.

The future of bladder cancer surveillance may involve using two types of liquid biopsies in tandem. A patient who is utDNA-positive but ctDNA-negative likely has a local, primary bladder issue. Conversely, a utDNA-negative but ctDNA-positive result suggests the cancer has already spread systemically, providing crucial information for treatment planning.

High relapse rates (~70%) in surgery-alone arms of recent trials suggest most patients with muscle-invasive bladder cancer (MIBC) already have micrometastatic disease. This reframes the disease, prioritizing early systemic therapy over immediate surgery to achieve control and potential cure.

Experts suggest urinary tumor DNA (utDNA) may better reflect local disease in the bladder, while circulating tumor DNA (ctDNA) indicates systemic disease. Using both tests in parallel could provide a more complete picture, with dual-negative results potentially becoming a key criterion for safely pursuing bladder-sparing approaches.

Professor Powles predicts a significant shift in bladder cancer treatment. High pathological complete response rates with neoadjuvant EV Pembro may allow responders, identified by imaging and circulating tumor DNA, to safely avoid radical cystectomy, a life-altering surgery that may become unnecessary for many.